Automatic safety cut-off for elevators.



PATENTED AUG. 29, 1905.

L. J. ADAMS.

AUTOMATIC SAFETY GUT-OFF FOR ELEVATORS.

APPLICATION FILED MAY 20, 1903.

"mm. mam-u m, Prow-umaanvums wnmmmn a UNITED STATES PATENT OFFICE.

AUTOMATIC SAFETY CUT-OFF FOR ELEVATORS.

Specification of Letters Patent.

Patented Aug. 29, 1905.

Application filed May 20, 1903. Serial No. 157,893

1'0 all whom it may concern.-

Be it known that I, LEON J. AnAMs, a citizen of the United States,residing at Providence, in the county of Providence and State of RhodeIsland, have invented a new and useful Improvement in Automatic SafetyOut- Otfs for Elevators, of which the following is a specification,accompanied by drawings forming a part of the same, in which Figure 1 isa side elevation, partly shown in section, of a safety cut-ofl forelevators embodying my invention and showing the position of theoperating parts when the electrical circuit is broken. Fig. 2 is a sideelevation of the same device, showing the position of the parts when thecircuit is closed.

Similar letters of reference refer to similar parts in both views.

The object of my invention is to provide a safety device adapted to beused with elevators in which the elevator-operating mechanism comprisesan electric circuit, the completion of which is necessary for theoperation of the elevator-car, and the device embodying my invention isadapted to break the electric circuit whenever the elevator-door isopened, and thereby prevent the movement of the car, rendering theelevator inoperative except when the elevator-door is closed.

Referring to the accompanying drawings, A denotes the elevator-door,represented in Fig. 1 as partially open and capable of a slidingmovement to bring it into contact with the door-jamb B when closed.Attached to the jamb B is a supporting-plate 0, upon which the operatingparts of my improved 7 safety eut-ofi' are mounted. Attached to theplate O by insulated connections are the brackets C and O. The bracket 0supports a cylindrical casing D and the posts E and F. Sliding insuitable hearings in the casing D and post E is a sliding bolt Gr,provided with a rectangular section G, which slides in the post E, andwith a brass tip G attached by an insulated joint Gr vwith therectangular section G. The casing D contains a spiral spring D, whichpresses against the end of the sliding bolt G to normally hold itsshoulder Gr against a stop-pin G held in the bracket O. In this positionof the bolt Gr its tip G projects through a suitable opening in theplate O and door-jamb B in the path of r the door A, so that theoperation of closing the door will impart a longitudinal movement to thesliding bolt Gr against the compression of the spiral spring D, forcingthe bolt from the position shown in Fig. 1 to the position shown in Fig.'2. The sliding bolt Gr is provided with a projecting shoulder G, which,as the bolt is pushed in by the closing of the elevator-door, is movedagainst the curved cam-surface H of a lever H, pivoted on a stud H,which is held in the post F. The inward movement of the sliding bolt Glifts the lever H from its normal position with its tip resting upon thecasing D, as shown in Fig. 1, to the position shown in Fig. 2. In theelevated position of the lever H, as shown in Fig. 2, it is supported bya latch I, which is pivoted at its lower end to the bracket O and isswung on its pivotal connection by the stud I, carried by the slidingbolt to bring the free end of the latch beneath a stud I held in thelever H.

Attached to the lever H is a blade-spring J, carrying at its free end anelectric contactplate J, which is brought by the upward rocking of thelever 11 against the contact-plate J which is supported by and insulatedfrom the. bracket O but has an electrical connection with the wire 7),forming part of the electric circuit. The lever H is electricallyconneeted with a wire a, also forming part of the electric circuit, sothat by the contact of the plates J and J the circuit is closed. \Vhenthe door A is moved away from the doorjamb B in the operation of openingthe door, the movement of the sliding bolt G is reversed by the tensionof the spiral spring D, which carries the shoulder Gr" away from thelever H; but the lever H is held in its elevated position by the latch Iuntil the latter is swung from beneath the stud I by means of the stud 1carried by the sliding bolt Or. The removal of the latch I permits thelever H to fall by gravity and to instantly open the circuit by theremoval of the plate J from the plate J when the operative parts of themechanism again assume their normal position, as shown in Fig. 1. Theupward movement of the lever H is continued for a short period after thecontact of the plate J against the plate J thereby causing a slightbending of the blade-spring J, as shown in Fig. 2, by which a pressureis applied to the contactplates equal to the elastic force of thebladespring J, and in addition the curvature of the spring causes aslight sliding movement between the contacting surfaces of the plates Jand J and a slight period of dwell is given to the contact-plate J, dueto the lost motion of the stud 1 before it is brought into contact withthe latch I on the reversal of the sliding bolt G. The contact of thestud l with the latch I near its pivoted end causes a quick movement ofthe free end of the latch, and the downward movement of the lever H bygravity is then accelerated by the elasticity of the blade-spring J,which is in a state of tension, thereby producing an instantaneous breakin the circuit. As the contact-plate J during the upward movement of thelever H approaches the contact-plate J in a line at substantially rightangles with their contacting surfaces the contact of the plate J withthe plate J is instantaneous and complete throughout its entire surface.

I am aware that safety cut-off devices for elevators comprising asliding bolt which is actuated by the movement of the elevatordoor isnot new; but the several features of construction and operation of myimproved device by which the circuit is maintained for a periodindependently of the movement of the door and in which thecontact-plates make an instantaneous face-to-face contact with theyielding pressure applied thereto and with a slight sliding movement ofthe contacting surfaces I believe to be broadly new.

In the operation of the mechanism, as above described, the reversal ofthe sliding bolt G and the separation of the contact-surfaces areeffected by means of the spiral spring D. As a precaution against thebreaking of the spring, I attach to the door-jamb B a bracket K,carrying a stud K, upon which I pivot a bellcrank lever L, having one ofits arms L provided with a slot U, which incloses a stud L on thesliding bolt G. The other arm L carries a'studL on which a roll L isarranged to be struck by the oblique edge M of a plate M, which isattached to the door A, so that the roll L will pass into the obliqueslot M as the door A is closed, and as the door is opened the obliqueedge M acting against the roll L will serve to rock the bell-crank L andreverse the motion of the sliding bolt G independently of the spring D.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In a safety cut-off for elevators, the combination with a slidingspring-actuated bolt projecting into the path of the elevator-door, of arigid pivoted lever, a movable contactplate carried by said lever, afixed contactplate in the path of said movable plate, means carried bysaid bolt for rocking said lever, thereby making a contact between saidcontact-plate and said movable plate, and means whereby said contact isbroken by the action of gravity.

2. In an elevator safety cut-off, the combination with a sliding boltprojecting into the path of the elevator-door, of a spring for reversingthe movement of said bolt, a shoulder on said bolt arranged to contactwith a pivoted lever, a pivoted lever, an electrical contact-platecarried by said lever, a fixed contactplate, a pivoted latch arranged tohold said lever with said plates in contact, and means carried by saidsliding bolt for actuating said latch, substantially as described.

3. The combination with a pair of contactplates forming electricalterminals, of means for bringing said terminals into contact comprisinga sliding bolt a stud carried by said bolt a pivoted lever carrying oneof said terminals, and arranged to be actuated by said sliding bolt, alatch by which said lever is held in position, and means carried by saidbolt for actuatingsaid latch,substantially as described.

4. In a safety cut-off for elevators, the combination of a sliding boltarranged to be moved in one direction by the closing of theelevatordoor, a spring by which the movement of the bolt is reversed, apivoted lever arranged to be lifted by said bolt, a latch for supportingsaid lever in an elevated position, means carried by said bolt foractuating said latch, a fixed contact-plate, a blade-spring carried bysaid pivoted lever, a movable contact-plate carried by saidblade-spring, and a shoulder on said bolt arranged to move said pivotedlever and impart a tension to said blade-spring as the contact-platesare brought together, substantially as described.

5. In a safety cut-off for elevators, the combination with a fixedelectric terminal, of a pivoted member, a terminal carried by saidpivoted member, means operated by the elevator-door for actuating saidpivoted member to bring the terminals into contact, a latch for holdingsaid terminals. in contact, and means for releasing said latch,substantially as described.

6. In a safety cut-off for elevators, the combination of a fixedterminal, a pivoted lever, a movable terminal carried by said lever, asliding bolt adapted to move said lever against gravity, a latch forsupporting said lever in its elevated position, a stud carried by saidbolt for moving said latch into engagement with said lever, anda studcarried by said bolt for disengaging said latch on the reverse movementof said lever, substantially as described.

7. In a cut-ofi for elevators comprising a pair of electric terminalsand a sliding bolt, of a bell-cranklever pivoted upon a fixed stud, withone of its arms operatively connected with said sliding bolt and havingits other arm extending into the doorway of an elevator, and anactuating-plate carried by the elevatordoor by which said bell-cranklever is rel by which said bell-crank is rocked as the door versed,substantially as described. is moved, substantially as described.

8. The combination With a pair of electric Dated this 9th day of May,1903. terminals of actuating mechanism for bring- 5 ing said terminalsinto contact and separating LEON ADAMS the same, and comprising aslidingbolt, a bell- \Vitnesses: crank lever operatively connected with saidRUFUs B. FOWLER,

bolt, and a plate carried by the elevator-door, PENELOPE (JoMBnRBAoH.

